On Wed, 2020-11-18 at 17:13 -0800, Jakub Kicinski wrote:
> On Tue, 17 Nov 2020 12:33:54 -0800 Saeed Mahameed wrote:
> > From: Maxim Mikityanskiy <maxi...@mellanox.com>
> >
> > tls_device_offload_cleanup_rx doesn't clear tls_ctx->netdev after
> > calling tls_dev_del if TLX TX offload is also enabled. Clearing
> > tls_ctx->netdev gets postponed until tls_device_gc_task. It leaves
> > a
> > time frame when tls_device_down may get called and call tls_dev_del
> > for
> > RX one extra time, confusing the driver, which may lead to a crash.
> >
> > This patch corrects this racy behavior by adding a flag to prevent
> > tls_device_down from calling tls_dev_del the second time.
> >
> > Fixes: e8f69799810c ("net/tls: Add generic NIC offload
> > infrastructure")
> > Signed-off-by: Maxim Mikityanskiy <maxi...@mellanox.com>
> > Signed-off-by: Saeed Mahameed <sae...@nvidia.com>
> > ---
> > For -stable: 5.3
> >
> > include/net/tls.h | 1 +
> > net/tls/tls_device.c | 3 ++-
> > 2 files changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/net/tls.h b/include/net/tls.h
> > index baf1e99d8193..a0deddfde412 100644
> > --- a/include/net/tls.h
> > +++ b/include/net/tls.h
> > @@ -199,6 +199,7 @@ enum tls_context_flags {
> > * to be atomic.
> > */
> > TLS_TX_SYNC_SCHED = 1,
>
> Please add a comment here explaining that this bit is set when device
> state is partially released, and ctx->netdev cannot be cleared but RX
> side was already removed.
>
> > + TLS_RX_DEV_RELEASED = 2,
> > };
> >
> > struct cipher_context {
> > diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> > index cec86229a6a0..b2261caac6be 100644
> > --- a/net/tls/tls_device.c
> > +++ b/net/tls/tls_device.c
> > @@ -1241,6 +1241,7 @@ void tls_device_offload_cleanup_rx(struct
> > sock *sk)
> >
> > netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
> > TLS_OFFLOAD_CTX_DIR_RX);
> > + set_bit(TLS_RX_DEV_RELEASED, &tls_ctx->flags);
>
> Would the semantics of the bit be clearer if we only set the bit in
> an
> else branch below and renamed it TLS_RX_DEV_CLOSED?
>
> Otherwise it could be confusing to the reader that his bit is only
> set
> here but not in tls_device_down().
>
Thanks Jakub, Maxim handled both comments, I will send V2 and drop the
other patch !
